Apparatus for applying liquid to corrugated sheet material



Al1g- 2, 1955 T. ROWLANDS 2,714,365

APPARATUS FOR APPLYING LIQUID TO CORRUGATED SHEET MATERIAL Filed Jan. 25, 1953 2,714,355 Patented Aug. 2, 1%55 APPARATUS FOR APPLYING LIQUID TO CGRRUGATED SHEET MATERIAL Tom Rowlands, Deptf-ord, London, England, assignor to Molina Machine Company Limited, London, England, a British company Application January 23, 1953, Serial No. 332,799

Claims priority, application Great Britain February 6, 1952 1 Claim. (Cl. 118-262) This invention concerns improvements in or relating to apparatus for applying liquid (e. g. liquid adhesive) by means of a roller, to a moving surface.

In the application of liquid adhesive to a moving surface it is often important to control the amount of adhesive supplied to the adhesive-applying roller, since the apparatus may be required to apply the adhesive to different surfaces which require different quantities of the liquid adhesive. For example in applying adhesive to corrugated board (with which this invention is particularly concerned) it is sometimes found that the quantity of adhesive which is correct for one grade ofboard is excessive for another, since some boards absorb or take up more adhesive than others. Excess of liquid adhesive is sometimes troublesome as the surplus adhesive falls away and clogs the apparatus, necessitating frequent stops for cleaning.

According to the present invention there is provided a device for regulating the quantity of liquid (e. g. liquid adhesive) supplied to an applying roller, comprising a regulating roller whose operative surface has grooves (e. g. helical grooves) extending transversely of its direction of movement, and raised portions between said grooves, the arrangement being such that on rotation of the regulating roller the said raised portions touch in succession the liquid-carrying surface of the applying roller while moving in the same general direction as the latter surface, means to supply liquid to a surface of at least one of said rollers (e. g. to a part of the surface of the applying roller) which is moving towards the position at which a raised portion of the regulating roller touches. the applying roller, and means to vary the speed of rotation of the regulating roller so as to vary the quantity of liquid carried beyond the regulating roller on the surface of the applying roller.

The liquid may be supplied directly to the applying roller from a bath or the like through which the lower part of the applying roller moves.

The grooves in the operative surface of the regulating roller may be arranged to extend along only a part of the length of said roller, the operative surface at one or both ends of the roller comprising unbroken raised portions which touch the surface of the applying-roller, whereby the supply of liquid to the latter is substantially limited to that part of its surface which corresponds to the grooved part of the regulating roller. In this way liquid may be applied to surfaces (e. g. paper webs) of diiferent widths by using different regulating rollers whose grooved parts correspond to the width of the surfaces to which liquid is to be applied. Or the regulating roller may be made, up of short interchangeable sections which can be changed in order to change the length of the grooved part.

Apparatus according to the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic view of the rollers of a corrugating machine.

Figure 2 is a view of a fragment of a roller shown in Figure 1, drawn to a larger scale.

paper board,

Figure 3 is a front elevation of a roller ure 1.

Referring to the drawings, the apparatus shown in Figure 1 forms part of a machine for making corrugated in which a web 1 of paper or board is passed between co-operating corrugated rollers 2 and 3 which form corrugations in the web, and then is joined to an uncorrugated web 4 which forms a liner, the two webs shown in Figbeing stuck together by adhesive which secures the tips of the corrugations to the surface of the liner. The adhesive is applied in liquid form to the tips of the corrugations in the corrugated web while the latter is still in the flutes of the corrugated roller 3, and is applied by means of an applying roller 5 whose lower part moves through a I bath 6 of liquid adhesive.

If too much liquid adhesive is carried by the applying roller, the surplus adhesive not taken up by the corrugated web tends to accumulate and build up on guides and other parts, not shown, but which are common features of such apparatus and thus necessitates frequent cleaning. This is particularly a disadvantage in the case of sodium silicate, an adhesive which is commonly used with corrugated board, and which dries into a very hard mass.

In order to regulate the quantity of adhesive supplied to the applying roller 5, a regulating roller 7 is arranged to co-operate with the latter at a position beyond that at which the liquid adhesive is supplied to the surface of the applying roller.

The regulating roller is arranged alongside the applying roller so that parts of its cylindrical operative surface touch the surface of the applying roller, and is so located that liquid adhesive carried upwardly by the latter from the bath must pass the regulating roller before reaching the position at which it is applied to the corrugated web. The cylindrical surface of the regulating roller 5 is smooth for a short distance 8, from each of its ends, see Figure 3, and touches the surface of the applying roller. The part 9 lying between these smooth end parts is provided with a number of grooves arranged helically about the roller with smooth raised portions between them which touch the applying roller. The shape of the grooves is shown in Figure 2 and the helical nature of the grooves is indicated diagrammatically in Figure 34. The spiral may be right or left-hand. The regulating roller is arranged to be rotated so that those portions of its operating surface which touch the applying roller do so While moving upwardly in the same general direction as the latterthat is, the regulating roller and applying roller are rotated in opposite directions.

The liquid supplied to the surface of the applying roller is carried up to the regulating roller, but only as much adhesive as can be accommodated in the grooves of the regulating roller will be carried beyond the latter, because the raised portions between the grooves, which successively touch the surface of the applying roller, each in turn act as a barrier to the passage of adhesive in excess of that within the grooves. It will therefore be seen that the amount of adhesive which can be carried past the regulating roller by the applying roller depends upon the capacity and the spacing apart of the grooves and upon the relative surface speeds of the applying roller and the regulating roller. Thus if the speed of rotation of the regulating roller be reduced while that of the applying roller remains constant, the rate at which adhesive can be carried past the regulating roller will be correspondingly reduced.

At each end of the regulating roller the whole of its unbroken cylindrical surface at 8 touches the applying roller and thus prevents adhesive from being carried past by the corresponding parts of the surface of the applying roller.

It will be understood that the raised portions of the regulating roller do not entirely prevent all adhesive from passing; in fact those parts of the applying roller which are touched by those raised portions do carry a small quantity of adhesive past the regulating roller, but this small quantity is in the nature of a thin film which does not tend to fall away from the applying roller or to transfer itself to other parts of the apparatus. Nor is this small quantity enough to affect the control of the supply by variation of the speed of the regulating roller, since the amount able to pass between the applying roller and the raised portion is insignificant compared with the amount which passes by way of the grooves.

A further roller 10 is located beneath. the regulating roller and close to the applying roller, and the regulating roller rests upon and is Wholly supported by this further roller (which will for convenience be called the supporting roller) and by the applying roller, the greater part of its weight being supported by the supporting roller. Thus no bearings are required for the regulating roller, but slotted end stops 11 are provided to maintain its lengthwise position and retain the roller substantially in its operative position. Since the apparatus is chiefly for use with very wide Webs of material the applying roller is of considerable length and therefore sags due to its weight, and by the arrangement 'described in which the regulating roller (which is of relatively small diameter) rests on the applying and supporting rollers, it can accommodate itself to Whatever curvature is assumed by the more rigid applying roller and can thus touch the surface of the latter in a substantially uniform way along its whole length. The regulating roller can be made additionally flexible by being made up of a number of short sections, loose on a shaft 12, and arranged end to end and pressed endwise into engagement with one another by the end stops. This arrangement is shown in Figure 3 and it will be understood that in such a case the spirals could easily be some right-hand and some left-hand.

The arrangement where the regulating roller is built up of a number of short pieces enables the length of the grooved part of the regulating roller to be varied when webs of different widths are used, by removing certain sections and replacing them by others. For example, to make the grooved part shorter, one or more grooved sections can be removed and replaced by smooth sections.

The regulating roller is frictionally driven by the supporting roller, which as stated above supports the greater part of its weight. The supporting roller is driven from the drive for the applying roller by any suitable and convenient variable speed gear whereby the speed of the supporting roller and thus of the regulating roller may be varied as required. As shown the rollers and are coupled by a V type belt 13 running on V pulleys 14 of the adjustable or expanding type.

The grooves on the regulating roller are, as stated above, arranged helically about the roller. The grooves could if desired be arranged parallel to the axis of the roller, but it is found preferable to arrange them helically so that at least one intermediate raised portion is always in contact with the applying roller.

In operation, when the machine is started up, the speed of the regulating roller is adjusted until the applying roller carries just enough adhesive to be taken up substan-' tially wholly by the corrugated board, with no appreciable surplus such as might transfer itself to other parts of the apparatus. If during operation conditions change-for example if a different kind or grade of board is used, which is either more or previously used-the speed of the regulating roller is again adjusted so as to increase or decrease respectively the amount of adhesive which can be carried on the surless absorbent than the board 4 face of the applying roller for application to the board.

Preferably the applying roller is rotated at a slower surface speed than that of the corrugated webfor example at half the speed of the web. As a result the liquid adhesive is in effect brushed off the surface of the applying roller by the tips of the corrugations in the web, and thus more adhesive is removed from the applying roller by the web than would be if the surface speeds were the same.

The arrangement whereby the supply of adhesive is substantially limited to the grooved part of the regulating roller, corresponding to the width of the corrugated web to which adhesive is to be applied, gives an important advantage over known methods of applying adhesive to corrugated board. It is sometimes the practice to supply adhesive to the whole length of the roller irrespective of the width of the web. According to that practice, in order to prevent adhesive being transferred to the exposed part of the corrugated roller beyond the edge of the web, th corrugated roller is arranged at such a distance from the applying roller that the Web has to leave the flutes of the corrugated roller and bow away from the latter to touch the applying roller so as to pick up adhesive. The web is able to do this because the arcuate guides, known as strippers, which hold it on the corrugated roller, are suitably cut away at an appropriate place to permit the web to leave the corrugated roller for this purpose.

It sometimes happens, however, that the corrugated web does not leave the flutes promptly and thus fails to contact the applying roller. This failure to leave the corrugated roller is particularly noticeable when the corrugated web is of a material which is not resilient enough to have a strong tendency to bow away from the corrugated roller.

By means of the present arrangement it is unnecessary to space the corrugated roller and the applying roller so far apart, and thus the corrugated Web touches the applying roller while remaining in the flutes, thus avoiding the ditficulties just described. Since the exposed end portions of the corrugated roller do not actually touch the applying roller they are unable to take up any of the thin film of liquid adhesive that may be on the end parts of the applying roller which are opposed to them.

What I claim as my invention and desire to secure by Letters Patent is z A device for regulating the quantity of liquid adhesive supplied to an applying roller, comprising a regulating roller whose operative surface has grooves extending transversely of its direction of movement, and raised portions between said grooves, the arrangement being such that on rotation of the regulating roller the said raised portions touch in succession the adhesive-carrying surface of the applying roller while moving in the same general direction as the latter surface, means to supply adhesive to that part of the surface of the applying roller which is moving towards the position at which a raised portion of the regulating roller touches the applying roller, and means to vary the speed of rotation of the regulating roller so as to vary the quantity of adhesive carried beyond the regulating roller on the surface of the applying roller.

References Cited in the file of this patent UNITED STATES PATENTS 801,563 Waterhouse Oct. 10, 1905 1,080,959 Eaton Dec. 9, 1913 1,439,464 Bowersock Dec. 19, 1922 2,176,607 Daley Oct. 17, 1939 2,181,798 Blackley Nov. 28, 1939 2,199,228 Obenshain et al. Apr. 30, 1940 2,294,513 Pearson Sept. 1, 1942 2,398,844 Muggleton et al. Apr. 23, 1946 2,531,036 Goettsch Nov. 21, 1950 

